1. Field of the Invention
The present invention relates generally to vents for use in permitting the passage of air from one defined space to another such as through the ceiling of a room into an attic space, and more particularly is directed to a vent that is unidirectional when closed and is capable of equalizing air pressure when sudden drops in outside pressure occur.
2. Description of the Relevant Art
It is frequently desirable to permit the venting of air from a room space into an attic which is in itself vented to the outside atmosphere. As a result of such an arrangement, when the attic is vented through active or passive means, the rooms which employ such automatic vents can also be similarly vented. For example, cool air can be permitted to enter the rooms and simultaneously, warmer air with contaminants, odoriferous aromas and moisture can be caused to rise to the ceilings of the rooms and through automatic vents mounted on the ceilings into the attic space so that they can be vented from the attic space and then out of the building. Ventilators which are employed to vent from attic areas, or the like, through roofs to the atmosphere are known in the art. Such devices include those shown in U.S. Pat. Nos. 4,123,001 and 4,210,277 invented by the inventor of the subject invention. Additionally, an automatic ceiling ventilator is disclosed in U.S. patent application Ser. No. 505,789 filed June 20, 1983, also by the same inventor as the present invention.
Other ventilators are also shown in U.S. Pat. Nos. 1,737,054; 3,921,900; and 3,976,245.
Unfortunately, for various reasons, including their large size and complexity, none of the presently known vents are capable of permitting air to flow outwardly (exhaust or vent into an attic) when closed and warm and/or odoriferous rising air currents are present. Furthermore these vents generally are unable to quickly equalize the air pressure within a room (defined space) when a sudden external (atmospheric) pressure drop occurs.
A simplified and compact construction of the ceiling vent is also desirable since this almost necessarily dictates a reduction in cost.
An additional disadvantage of known devices is that they are maintained in an entirely closed position until the temperature of the temperature responsive mechanisms is reached. In certain instances the entire blockage of air flow is not desirable and it may be desirable to permit minimal air flow regardless of the temperature of the air proximate the venting device. An apparatus for providing air flow with minimal rising air currents has not been disclosed in the relevant art.
The present invention overcomes the shortcomings associated with the relevant art by providing an automatic unidirectional vent for permitting the passage of air from one defined space to another which includes a device for permitting the desired air flow even when the vent is in a closed position. In addition, the present invention includes an apparatus for equalizing air pressure if the outside (atmospheric) pressure suddenly drops. Moreover, the instant invention can be installed in a ceiling opening from the room side of such opening with minimal effort and expense.